1. Field of the Invention
The present invention relates to an image display apparatus, an image capturing apparatus, and a method of controlling the image display apparatus.
2. Description of the Related Art
A conventional image capturing apparatus performs a so-called developing process including debayering (de-mosaicing) raw image information (RAW image) captured by an image sensor, converting the information into signals formed from a luminance signal and color difference signals, and performing noise reduction, optical distortion correction, and image optimization for each signal. In general, then, the apparatus compression encodes the luminance and color difference signals having undergone the developing process by a coding scheme such as JPEG and records the resultant signals in a recording medium.
Some image capturing apparatuses can record a RAW image. Although a RAW image contains an enormous amount of data required for recording, it is possible to suppress correction and degradation with respect to the original image to the minimum and to perform editing after image shooting. For this reason, advanced users like to use such apparatuses.
With advances in image sensors, the number of pixels per image in recent image capturing apparatuses has greatly increased. In addition, there is a tendency to increase the number of images which can be continuously captured per sec. This synergistically increases the throughput required to perform a developing process including a debayer process, noise removal, and optical distortion correction for a RAW image, resulting in requiring an enormous circuit and power consumption for performing a developing process in real time concurrently with image shooting. In some cases, the occupation of a circuit by a developing process and a limitation on power consumption can lead to incapability to implement high image shooting performance.
On the other hand, as disclosed in Japanese Patent Laid-Open No. 2011-244423, in the arrangement configured to record a RAW image without developing it, although the throughput associated with developing at the time of image shooting may be reduced, it is difficult to quickly play back/display the image, because the image is recorded in an undeveloped state. As described above, the conventional RAW image recording scheme has sometimes degraded the convenience for the user.
In contrast to this, Japanese Patent Laid-Open No. 2006-229474 has proposed a method of generating a JPEG image for playback/display and recording it together with a RAW image in a recording medium at the time of RAW image recording. The above JPEG image for playback/display is designed to be displayed/played back on a display apparatus such as a liquid crystal monitor which an image capturing apparatus generally has. Although it depends on the resolution of a display apparatus, a JPEG image for playback/display is generally lower in resolution than a RAW image and a JPEG image to be recorded in a recording medium, and hence is low in throughput. Therefore, even if a JPEG image for playback/display is processed parallel to RAW image recording, the load does not increase.